Water level control



y 1967 B. E. STEWART ETAL 3,331,374

WATER LEVEL CONTROL Filed Oct. 4, 1965 2 Sheets$heet l y 1967 a. E. STEWART ETAL 3,333,374

WATER LEVEL CONTROL 2 Sheets-Sheet 2 Filed Oct. 4, 1965 United States Patent 3,331,374 WATER LEVEL CONTROL Bruce E. Stewart, 1107 Burns, St. Paul, Minn. 55106, and John B. Lyman, 2221 E. Old Shakopee Road, Bloomington, Minn. 55420 Filed Oct. 4, 1965, Ser. No. 492,635 7 Claims. (Cl. 13456) ABSTRACT OF THE DISCLOSURE A liquid level and flow control having a drain outlet and a return outlet with a solenoid-operated valve for selectively closing the drain outlet. A float is attached to the valve to open the valve as the result of a high liquid level condition, even though the solenoid is de-energized, thereby to limit the level. The valve is provided with a deflector which assists the solenoid in urging the valve to the outlet-closing position. Further, the float is arranged to normally bias the valve to the outlet-closing position, and is moved by the solenoid during the normal operation of the solenoid to effectively maintain the float freely operative.

This invention relates to washing apparatus and in particular to apparatus for washing dishes and the like having means for pumping liquid from the apparatus to a drain.

In one known apparatus for washing dishes and the like, a drain pump is provided for pumping the washing liquid to a suitable drain such as upon completion of a washing cycle. In a conventional form of such dishwasher apparatus, a recirculation pump is further provided for pumping water to a spray device arranged to spray the washing liquid onto the dishes and thereby provide an improved dishwashing operation. In such dishwashers having both a drain pump and a recirculation pump, it has been heretofore conventional to provide a reversible drive motor so that the drain pump is operable upon rotation of the motor in one direction while the recirculation pump is operable upon rotation of the motor in the opposite direction. Such reversible motors, however, are relatively expensive and, thus, it is desirable to eliminate the need for such reversible motors if at all possible.

One proposed solution to this problem has been to provide a drain pump which operates concurrently with the recirculation pump, but which has the flow therefrom directed to a suitable control which selectively returns the liquid pumped by the drain pump back to the dishwasher, or pumps the liquid to the drain.

Another problem encountered in such dishwasher apparatus is the problem of positive overflow prevention. In the event that the inlet water control malfunctions and continues to deliver water to the dishwasher after the desired quantity is delivered thereto, serious flooding may occur. To preclude this, relatively expensive devices such as weight or pressure responsive controls for sensing the level in the dishwasher have been provided.

The present invention comprehends an improved control means for selectively directing the delivery of the liquid from the drain pump to a drain or back to the dishwasher as desired and which is further arranged to provide a drain from the dishwasher in the event that the inlet valve malfunctions and improperly continues to deliver water to the dishwasher. Thus, a principal feature of the present invention is the provision of a new and improved control for use in a washing apparatus such as a dishwasher or the like.

Another feature of the invention is the provision of such a control having new and improved means for selectively directing the liquid from the drain pump to a drain or back to the dishwasher as desired.

- vided with 3,331,374 Patented July 18, 1967 'ice A further feature of the invention is the provision of such a control further arranged to provide an automatic draining of the dishwasher in the event that the level of liquid in the dishwasher rises above a preselected level such as may occur by a malfunctioning of the inlet water supply valve.

Still another feature of the invention is the provision of such a control having a new and improved swing valve means for controlling the delivery of liquid from the drain pump to a drain outlet.

A yet further feature of the invention is the provision of such a control having means for operating the valve means to open the outlet means in a drain cycle of operation of the dishwasher, and means responsive to the level of liquid in the dishwasher to open the outlet means in the event that the level of liquid rises above a preselected level such as during a fill cycle of operation of the dishwasher.

Still another feature of the invention is the provision of such a control wherein the level responsive means includes a float in the washing chamber of the dishwasher.

A further feature of the invention is the provision of such a control having a new and improved swing valve including a baflle portion and an open portion, and means for selectively pivoting the swing valve so as to alternatively dispose the bafile portion across the drain outlet and align the open portion with the drain outlet.

A yet further feature of the invention is the pro-vision of such a control including stop means for limiting the pivotal movement of the swing valve in each of the above indicated positions.

Another feature of the invention is the provision of such a control wherein the swing valve is further provided with a deflector for biasing the valve to said outlet blocking position as a result of impingement of the liquid delivered from the drain pump thereagainst.

Other features and advantages of the invention will be apparent from the following description taken in con nection with the accompanying drawing wherein:

FIGURE 1 is a fragmentary elevation of a dishwasher having a control embodying the invention, with portions of the dishwasher being shown in vertical section for facilitated illustration of the invention;

FIGURE 2 is a fragmentary vertical section of the control arranged in a drain-outlet blocking position;

FIGURE 3 is a fragmentary vertical section of the control arranged to permit flow of liquid from the drain pump to the drain outlet;

FIGURE 4 is a vertical section taken substantially along the line 44 of FIGURE 3; and

FIGURE 5 is a horizontal section taken substantially along the line 55 of FIGURE 2.

In the exemplary embodiment of the invention as disclosed in the drawing, a dishwasher generally designated 10 is shown to comprise a tub 11 having a lower sump portion 12. Washing liquid such as hot water is delivered into the tub 11 through a suitable inlet conduit 13 proa conventional inlet control valve 14. As shown in FIGURE 1, the washing liquid collects in the sump portion 12 to a preselected level L. The articles to be washed such as dishes and the like (not shown) are disposed within the tub 11 above a rotatable spray arm 15. The washing liquid is sprayed upwardly from the spray arm by means of a recirculation pump 16 which pumps the washing liquid upwardly through a suitable hollow shaft 17 from the sump portion 12. A drain pump 18 pumps the washing liquid W from the sump through a conduit 19 to a flow control 20 for selective delivery to a drain outlet 21 or back to the sump portion 12 of the tub 11. Thus, each of the pumps 16 and 18 may be driven by a single electric motor 22 which need rotate in only a single direction and, thus, may be a relatively economical unidirectional motor.

As shown in FIGURE 1, the flow control 20 includes a housing 23 which is carried by a horizontal portion 24 of the tub wall disposed slightly above the normal full water level L. As shown in FIGURE 2, the tub wall portion 24 is provided with an opening 25 providing communication between the control chamber 26 within housing 23 and the washing chamber 27 defined by tub 11. A screen 28 may be secured to the tub wall portion 24 to bridge the opening 25 thereby filtering material from the liquid passing upwardly therethrough back to the washing chamber 27.

As shown in FIGURE 4, an inlet fitting 29 is formed integrally with one wall 30 of the flow control housing 23 and an outlet fitting 31 is formed integrally with the opposite wall 32 of the housing 23. The conduit 19 is connected to an outer end 33 of the fitting 29, and the drain conduit 21 is connected to the outer end 34 of the fitting 31. As shown in FIGURE 4, the fittings 29 and 31 may be integrally joined by a mid-portion 35 which defines a pair of spaced uprights 36 and 37 between which a swing valve plate 38 is movably mounted on a pivot pin 39. The outlet fitting 31 includes within control chamber 26 a venturi portion 40 which at its inner end defines the drain opening 41 leading from the chamber 26 to the drain conduit 21 through the fitting 31. The inlet fitting 2.9 includes in chamber 26 a venturi portion 42 aligned with outlet opening 41 and having a discharge opening 43 spaced closely thereto on the opposite side of the swing valve plate 38 as shown in FIGURE 4.

As best seen in FIGURES 2 and 3, the swing valve plate 38 includes a bafile portion 44 and an opening 45 with a forwardly projecting deflector 46 carried on the plate intermediate the portions 44 and 45 to be disposed in the path of liquid delivery through opening 43 when the swing valve plate is in the outlet blocking position of FIGURE 2. As best seen in FIGURE 5, the deflector 46 includes an arcuate portion 47 against which the liquid impinges and urges the plate 38 in a counterclockwise direction, as seen in FIGURE 2, to cause a corner portion 48 of the plate to abut an upstanding stop rib 49 on the housing 23. As shown in FIGURE 2, in this position the baflle portion 44 effectively blocks the outlet opening 41 and, thus, liquid entering the control housing chamber 26 is prevented from passing outwardly through the drain conduit 21 but rather is directed upwardly through the screen 28 into the washing chamber 27 for return to the sump 12, thereby maintaining the quantity of washing liquid W in the sump substantially at the level Thus, in this position of the swing valve plate 38, the pump 18 recirculates the washing liquid from the sump back into the chamber 27 and thence back to the sump while the pump 16 is directing the liquid upwardly through the spray arm 15 to effect a washing operation.

Upon completion of the washing operation, the washing liquid may be discharged to the drain conduit 21 by repositioning of the swing valve plate 38 to the position of FIGURE 3. As shown in FIGURE 3, in this position the opening 45 is aligned with the drain opening 41 of the outlet fitting 31 and, thus, liquid delivered from conduit 19 through fitting 29 is directed into outlet opening 41 and thence through the drain conduit 21 to a suitable drain (not shown). In the illustrated embodiment the movement of the plate 38 is effected by a solenoid generally designated 50 having a coil 51 and an armature 52 which when the coil 51 is suitably electrically energized is drawn to the left as seen in FIGURE 3. A connecting rod 53 is secured at one end to the solenoid armature 52 and at the other end pivotally encircles a pin 54 carried by the plate 38 so as to provide for swinging movement of the plate 38 as discussed above. As shown in FIGURE 3, the clockwise pivotal movement of the plate 38 is limited by the abutment of a shoulder 55 on the plate with an upstanding stop rib 56 on the housing 23, thereby accurately aligning the plate opening 45 with the drain opening 41 in this position of the swing valve plate 38. Thus, in this position of the plate 38, liquid delivered from conduit 19 passes freely from the inlet fitting 29 through the outlet opening 41 of outlet fitting 31 and thence to the drain conduit 21. Operation of solenoid 50 may be by a suitable conventional control, such as control 58 in FIGURE 1.

Upon de-energization of the solenoid coil 51, the swing valve plate 38 tends to swing back to the position of FIGURE 2 wherein the baffle portion 44 blocks the flow of liquid from the inlet opening 43 to the outlet opening 41. The plate 38 is self-biasing in this respect as it tends to normally move to this position under the influence of gravity.

As indicated briefly above, the invention further comprehends the provision in apparatus 10 of means for draining washing liquid from the washing chamber sump 12 in the event that the level L of the washing liquid rises above the preselected level as when the inlet valve 14 malfunctions and continues to deliver water to the washing chamber after a proper quantity of water has been delivered thereto. As best seen in FIGURES 2 and 3, the flow control means includes a float member 59 comprising a downwardly opening cup element disposed in washing chamber 27 slightly above the wall 24. The float member 59 is provided with a depending boss 60 which is connected by means of a link rod 61 to an arcuate arm 62 on the plate 38 extending outwardly from bafflle portion 44 upwardly toward the float member 59. Thus, when the level of liquid in the washing chamber rises above the preselected level L, such as for example to the abnormally high level L shown in FIGURE 2, the float member 59 pivots the plate 38 in a clockwise direction as seen in FIGURE 2 to the unblocking arrangement of FIGURE 3 whereupon washing liquid flowing through conduit 19 from pump 18 is discharged from the sump 12 into the drain conduit 21, thereby preventing undesirable overflow. The fact of the malfunctioning of the valve 14 causing the continuing delivery of liquid to the dishwasher and the continuing draining thereof by the above indicated means will be quickly called to the attention of the user, whereupon suitable steps may be taken to rectify the condition.

Float member 59 further serves to augment the biasing of the plate 38 to the drain blocking position of FIGURE 2 as a result of the weight thereof acting through the link 61 on the plate arm 62 further urging the plate to the counterclockwise extreme position of FIGURE 2 wherein the corner 48 abuts the stop 49. As shown in FIGURES 2 and 3, the link 61 may project upwardly through a small opening 63 in the wall 24 and a corresponding small opening 64 in the screen member 28. As the float 59 is moved upwardly directly as the level of washing liquid in the washing chamber 27 rises, the opening 45 is moved progressively further and further into alignment with the drain outlet opening 41 until it reaches full alignment therewith as shown in FIGURE 3.

Thus, fluid flow control 20 provides an improved control of the flow of liquid delivered from drain pump 18 as during normal dishwashing and drain cycles by respectively returning the washing liquid to the washing chamber and directing it to the drain conduit, thus permitting the use of a unidirectional motor 22 for ope-ration of the recirculation pump 16 and drain pump 18. In addition, the fluid flow control 20 provides an automatic means for preventing overflow in the dishwasher as may result from a malfunctioning of the water spray inlet valve. The fluid flow control is extremely simple and economical of con struction while providing long trouble-free life and because of the simple arrangement substantially minimizes maintenance requirements.

While we have shown and described one embodiment of our invention, it is to be understood that it is capable of many modifications. Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention as defined in the appended claims.

The embodiment of the invention in which an exclusive property or privilege is claimed is defined as follows:

1. In a dishwasher having means defining a washing chamber having a sump portion, means for delivering liquid to said chamber to fill said chamber to a preselected level, drain means for conducting liquid away from said chamber, and means for pumping liquid from said sump portion of the chamber, means for directing liquid flow from said pumping means selectively back to said chamber to maintain said level or to said drain means to remove said liquid from said chamber, including means movable with said directing means and responsive to the level of liquid in said washing chamber to cause said directing means to direct said liquid to said drain means in the event that the level of liquid in said chamber rises above said preselected level, said level responsive means comprising means for progressively uncovering the drain means in direct relationship to the height of said liquid level above said preselected level.

2. The dishwasher means of claim 1 wherein said level responsive means comprises a downwardly opening cup member defining a float in said washing chamber responsive only to levels of liquid in said washing chamber above said preselected level.

3. The dishwasher means of claim 1 wherein said level responsive means and the directed liquid bias the blocking means toward the drain blocking arrangement.

4. The dishwasher means of claim 1 wherein said blocking means includes means responsive to the directed liquid to bias the blocking means to the blocking arrangement.

5. 'In a dishwasher having means defining a washing chamber having a sump portion, means for delivering liquid to said chamber, drain means for conducting liquid away from said chamber, and means for pumping liquid from said sump portion of the chamber, means for controlling liquid flow from said pumping means selectively to said drain means or back to said chamber, comprising:

means defining a control chamber;

means defining a flow passage between said control chamber and said washing chamber;

means for directing liquid from said pumping means through said control chamber and to said drain means;

a swing valve plate having a bafiie portion and an open portion;

means for pivotally mounting said valve plate in said chamber;

means for selectively disposing said baffle portion across said drain means in one pivotal position of the plate for causing the liquid directed by said directing means to pass through said control chamber to said flow passage for return to said washing chamber and disposing said open portion in alignment with said drain means for exposing said drain means in another position of the plate to permit said liquid to flow from said directing means into said drain means.

6. The dishwasher means of claim 5 wherein said plate further includes a deflecter arranged to extend in the path of the directed liquid to bias the plate to said one pivotal position as the result of the impingement of the directed liquid thereagainst.

7. The dishwasher means of claim 5 wherein said control chamber means further includes stop means for engaging spaced portions of the plate to iimit the pivotal movement of the plate.

References Cited UNITED STATES PATENTS 187,181 2/ 1877 Schmitz 137-448 X 356,448 1/1887 Clark 137448 1,399,97'8 12/1921 Mon'aghan 134-56 3,078,858 2/1963 Jacobs et a1. 13457 CHARLES A. WI-LLMU 'IH, Primary Examiner. R. L. BIJE'UTGE, Assistant Examiner. 

1. IN A DISHWASHER HAVING MEANS DEFINING A WASHING CHAMBER HAVING A SUMP PORTION, MEANS FOR DELIVERING LIQUID TO SAID CHAMBER TO FILL SAID CHAMBER TO A PRESELECTED LEVEL, DRAIN MEANS FOR CONDUCTING LIQUID AWAY FROM SAID CHAMBER, AND MEANS FOR PUMPING LIQUID FROM SAID SUMP PORTION OF THE CHAMBER, MEANS FOR DIRECTING LIQUID FLOW FROM SAID PUMPING MEANS SELECTIVELY BACK TO SAID CHAMBER TO MAINTAIN SAID LEVEL OR TO SAID DRAIN MEANS TO REMOVE SAID LIQUID FROM SAID CHAMBER, INCLUDING MEANS MOVABLE WITH SAID DIRECTING MEANS AND RESPONSIVE TO THE LEVEL OF LIQUID IN SAID WASHING CHAMBER TO CAUSE SAID DIRECTING MEANS TO DIRECT SAID LIQUID TO SAID DRAIN MEANS IN THE EVENT THAT THE LEVEL OF LIQUID IN SAID CHAMBER RISES ABOVE SAID PRESELECTED LEVEL, SAID LEVEL RESPONSIVE MEANS COMPRISING MEANS FOR PROGRESSIVELY UNCOVERING THE DRAIN MEANS IN DIRECT RELATIONSHIP TO THE HEIGHT OF SAID LIQUID LEVEL ABOVE SAID PRESELECTED LEVEL. 